In an LTE-Advanced scheme, a mobile station UE is configured to be able to perform a CA (Carrier Aggregation) communication with a radio base station eNB by using a plurality of DL CCs (Downlink Component Carriers) and a plurality of UL CCs (Uplink Component Carriers), which have carrier frequencies different from each other.
As illustrated in FIG. 7, in the LTE-Advanced scheme, each CC used in the CA communication can be set in an active state or a deactive state.
Furthermore, in the LTE-Advanced scheme, the mobile station UE is configured to control transmission power in PUSCH (Physical Uplink Shared Channel, an uplink shared channel), transmission power in PUCCH (Physical Uplink Control Channel, an uplink control channel), transmission power of SRS (Sounding Reference Signal), transmission power in PRACH (Physical Random Access Channel), and the like on the basis of path loss (Pathloss) estimated from predetermined DL CC.
Furthermore, the mobile station UE is configured to calculate the path loss in the predetermined DL CC by using the difference between transmission power (Resource Element unit) of a downlink common pilot signal (a cell-specific reference signal) in the radio base station eNB and received power (Resource Element unit) of the downlink common pilot signal in the mobile station UE.
In addition, the transmission power of the downlink common pilot signal in the radio base station eNB is broadcasted by the radio base station eNB.
Furthermore, there has been a discussion that the mobile station UE is notified from the radio base station eNB of from which DL CC the path loss used for controlling the transmission power in each UL CC should be calculated.
However, the applicant found the following problems in the aforementioned LTE-Advanced scheme.
In the LTE-Advanced scheme, the mobile station UE does not frequently monitor DL CC in a deactive state, and thus it is not possible to ensure the estimation accuracy of path loss in the DL CC.
Therefore, it is not possible to ensure the accuracy of transmission power control of UL CC based on the path loss, and thus there is a problem that the transmission of an uplink signal in the UL CC may be an additional interference factor.
Therefore, the present invention has been achieved in view of the above-described problems, and an object thereof is to provide a mobile communication method and a mobile station, by which it is possible to reduce interference in a CA communication.